PROJECT SUMMARY Unprecedented growth in the proportion of older adults in the U.S. has placed inequalities in healthy aging at the forefront of the public health agenda. Individuals often differ dramatically in their speed of aging. Some demonstrate accelerated aging and suffer early onset of chronic illness whereas others manifest decelerated aging and stave off serious illness well into their 90s. In recent years, researchers have made much headway in understanding the molecular markers of healthy aging, thereby allowing for earlier identification of risk for chronic disease. The proposed research focuses on two such biomarkers of healthy aging ? inflammatory aging and methylomic aging. These measures provide us with ?biological clocks? that are strongly predictive of age-related physiological decline, disease, and mortality. Having established these molecular measures of the speed of aging, the important question for social scientists and health policy now becomes: To what extent is the speed of aging malleable, for better or worse, in response to natural shifts in psychosocial contexts? This question is the focus of the present proposal. We plan to investigate the extent to which adult social conditions from various domains, but especially those operating within the family, influence speed of biological aging after taking into account childhood experiences and potentially confounding life style factors such as diet, exercise, and smoking. Our objective is to identify the stressors that accelerate aging as well as the supports that decelerate aging. These goals will be pursued using longitudinal data from the Family and Community Health Study (FACHS), a 20-year study of well-being among African American mothers, their romantic partners (RPs), and their offspring. A focus on aging among African Americans is important as they tend to suffer from earlier onset and higher prevalence of age-related diseases and a wider range of psychosocial stressors than other ethnic groups. First, we will obtain longitudinal indices of the speed of inflammatory and methylomic aging from the now middle-aged mothers and, if partnered, their RPs by collecting and assaying a new wave of blood data, as well as assaying stored blood from a previous wave. The proposed data will provide the first comprehensive assessment of change in the speed or rate of biological aging during adulthood. Second, we will collect an additional wave of interview data so that changes in supports and stressors can be mapped onto changes in the rate of biological aging.